When used with biomes o plenty, mobs from dungeons mobs, dannys expansion and greek fantasy don't spawn even though they use biome dictionary to spawn mobs (or if they do, very rarely). Structures from valhesia structures, when dungeon arises and hunterillager spawn a lot less often as well.

API/Modloader
Forge

To Reproduce
Install the above mods, and turn the spawn rates of the structures and mobs to 10x more
Start a world
Fly around and check if mobs spawn

Expected behavior
mobs spawning, and structures spawning much more frequently

Additional context
1.16.4 Forge latest version 35.1.37
byg 1.1.8

This really seems like a BOP issue. We utilize the Forge Biome Dictionary on all of our biomes, if a structure or mob mod fails to utilize the biome dictionary we can't fix that for them.

Unless there is visible proof that it is BYG's fault this will remain closed.